Bracket mounting for bulldozer support frame or the like



Nov. 27, 1962 H. w. FALL 3,065,980

' BRACKET MOUNTING FOR BULLDOZER SUPPORT FRAME OR THE LIKE Filed March31, 1960 2 Sheets-Sheet 1 IN V EN TOR. 144 7-77 7.7.

ATTORNEYS BY v y. 2 i lwwe Nov. 27, 1962 H. w. FALL 3,065,980

BRACKET MOUNTING FOR BULLDOZER SUPPORT FRAME OR THE LIKE Filed March 51,1960 2 Sheets-Sheet 2 ELE E 28 27 Z6 26 970m @111 24 I P/P/QPAPTINVENTOR.

Mr L

- ATTORNEYS United States Patent Gfiiice amass Patented Nov. 27, 19623,065,980 BRACKET MOUNTING FOR BULLDOZER SUPPGRT FRAME OR THE LIKE HarryW. Fall, Morton, Ill., assignor to Caterpillar Tractor (30., Peoria.lll., a corporation of California Filed Mar. 31, 1960, Ser. No. 18,947 1Claim. (Cl. 287-202) This invention relates to the mounting or securingof load sustaining brackets on a hollow frame or other plate-likestructure by welding wherein concentrated stresses are likely to causefracture of the frame adjacent the bracket.

The invention is disclosed herein in its application to the C-frame ofan angling type bulldozer wherein it has proven particularly effectivebut its usefulness in other environments will be come apparent from thedescription which follows.

It is an object of the invention to provide an improved method forsecuring a load sustaining bracket to a plate or member fabricated fromplate-like parts and to provide a structure of greater strength than isattained by welding a bracket directly to the surface of such a member.

it is a further object of the invention to provide a bulldozer frame ofsuperior strength by employing a method of securing brackets theretowhich does not induce a concentration of stresses in the areas subjectto heavy loading.

Further and more specific objects and advantages of the invention aremade apparent in the following specification wherein the invention isdescribed in detail by reference to the accompanying drawings.

In the drawings:

FIG. 1 is a schematic plan view of a tractor with an angling typebulldozer mounted thereon and showing the positions of the brackets withwhich the present invention is concerned;

FIG. 2 is a fragmentary side sectional view of the C- frame showing thebracket secured to the C-frame in accordance with the present invention;and

FIG. 3 is a view similar to FIG. 2, but illustrating a conventionalbracket securing method, and indicated as the prior art.

The tractor shown at 10 in FIG. 1 of the drawings is provided with anangling type of bulldozer which comprices a C-frame 11 pivotally securedto the track roller frames of the tractor not shown by means oftrunnions 12. The blade 13 is connected at a central point to theforward end of a C-frame, as by a pivot pin 14, and angle braces 15extend between the outer ends of the blade rearwardly to brackets 16welded to the top of the C-frame. The blade is illustrated in itsstraight position but may be angled to one side of the other by the useof auxiliary brackets shown as two rear back brackets 17 and two frontbrackets 18. The braces 15 are connected with the brackets by taperedpins 19' which are received in tapered openings in the brackets and areprovided with spherically contoured outer ends for connection with theends of the braces.

To dispose the blade at an angle, one of the braces is moved to a rearbracket 17 on one side of the C-frame and the other is moved to a frontbracket 18 on the opposite side. In this position of the blade, thefront bracket which is being used is subjected to heavier loads than theother brackets when they are in use and failures have been encounteredin the area of the frame immediately adjacent the bracket and usuallydirectly behind it.

C-frames are conventionally formed as a hollow beam fabricated fromsteel plate sections welded together and the failures which have beenencountered have been analyzed as resulting from the concentration ofstresses at a point where there is an abrupt change in section orthickness of the stressed material. This may readily be understood fromFIG. 3 showing a conventional bracket 18 secured in place on the C-frame11 as by a fillet weld 21. Due to the nature of the'load applied to theC-frame when the bulldozer blade is in its angled position, the topportion of the frame in the area of the front bracket is placed intension by a force which tends to bend the frame and consequentlyfailures in the form of cracks such as indicated at 22 in FIG. 3 occurin the area where a stress riser has been caused by the abrupt change inthickness of material caused by welding the bracket 18 to the platewhich forms a part of the C-frame. Such failures have been obviated bythe present invention by a method and construction which serves tolocate the Weld in areas of low nominal stress or in an area ofincreased section and, therefore, greater strength.

The attachment of a bracket to a C-frame in accordance with the presentinvention is shown in FIG. 2 wherein a bracket is shown as comprising aforged plate 24 with a bracket extension 25 welded thereto. The plate 24has a circumscribing flange or marginal thickness which is the same asthe plate of which the C-frame is fabricated and is secured, within anopening which has been cut in the ()frame for its reception, by a fullpenetration V-butt weld as shown at 26 so that this weld is placed in anarea of constant section rather than in an abrupt change in section suchas the weld 21 of FIG. 3. It is possible in accordance with the presentinvention to make the entire bracket shown in FIG. 2 as a single forgingbut since forgings of this general shape are complicated and costly tomake, the portion 24 is formed with an integral base for the portion 25of greater thickness than its marginal edge and joined thereto by alarge radius fillet as shown at 27. The member 25 is then secured inplace as by a Weld 28 at an area which because of its greater thicknesshas greater strength and is less subject to failure. Thus by positioningthe weld in areas of low stress and great strength, the presentinvention has overcome failures which were experienced in structures ofconventional design.

I claim:

A C-frame for a tractor comprising a hollow beam fabricated from steelplate sections welded together, said sections being of substantially thesame thickness, the top section of said beam having an opening cuttherein for reception of a steel plate insert therein, a steel plateinsert disposed in said opening having an undersurface flush with theundersurface of the contiguous portions of said top section, a V-buttweld disposed in said top section around the perimeter of said insertand extending completely through said opening and joining said insert tothe surrounding marginal portion of said top section, said insert havinga top surface substantially flush with the top of said adjacent V-buttweld and the adjacent upper surface of said top section, said topsurface of said insert extending inwardly thereof a substantial distancefrom its marginal edge and having an upwardly extending portionproviding a central portion of substantially greater thickness than itsmarginal edge and of constant thickness and the central portion andmarginal edge being joined by a fillet portion, a vertical bracketmember seated on said thickened central portion having an openingtherein to receive a pivot pin for mounting a tractor blade thereon, theopposite bottom sides of said bracket adjacent the edges of saidthickened central portion being provided with oppositely disposedrecesses, and a weld disposed in each said recess joining said bracketand the marginal edge of said central portion together, said bracketwelds 3 4 being formed to be substantially flush with said fillet2,381,890 Ebbets Aug. 14, 1945 portion and the contiguous bracketsurface. 2,561,938 Mei-1g July 24, 1951 2,569,632 Hauck Oct. 2, 1951References Cified in the file Of this patent 2,942,} 63 Long June 28,1960 2 050 339 221? STATES PAiEN i 11 1936 o FOREIGN PATENTS 1 g-2,177,127 Harter Oct. 24. 1939 4731095 Germany 1929

